[Arthroscopic treatment of the ulnar impaction syndrome.]

The ulnar impaction syndrome is due to hyperpressure in the ulnocarpal joint. It occurs most frequently following distal radial fractures with shortening, but can also be secondary to a primitive length discrepancy between a short radius and a long ulna (positive ulnar variance). Symptoms and clinical findings, even though characteristic, are not specific. Standard X rays show a positive ulnar variance, and sometimes a hyperpressure cyst in the lunate. CT arthroscan and MRI studies demonstrate indirect signs of hyperpressure. If medical treatment fails to improve the condition, the choice surgical technique is arthroscopic, allowing debridement of the TFCC central tear, and shortening of the horizontal aspect of the ulnar head.